Predictive Factors for Renal Outcome During Remission Induction Treatment Period in Lupus Nephritis

Objectives Patients with refractory lupus nephritis (LN) may benefit from the addition of anti‐lupus drugs to standard remission induction therapy; however, which patients require additional treatment remains unclear. This study aimed to identify the predictive factors for renal outcomes during standard remission induction treatment for LN. Methods This retrospective observational study included 85 LN patients with standard remission induction therapy between 2006 and 2020. The baseline was the day of the initiation of remission induction therapy. Clinical and laboratory data were collected at 0, 2, 4, 8, 12 and 52 weeks after baseline. Complete renal remission (CRR) was defined as proteinuria < 0.5 g/gCr plus estimated glomerular filtration rate no worse than 10% below preflare value or ≥ 90 mL/min/1.73 m 2 at 52 weeks. Results Among 85 patients, 48 (56.5%) achieved CRR at 52 weeks. Baseline serum creatinine (Cr) and proteinuria levels were not significantly different between the CRR and non‐CRR groups. In the CRR group, the rate of decrease (%) in serum Cr at each period from baseline was significantly higher, while proteinuria at 12 weeks was significantly lower. Multivariate logistic regression identified the rate of decrease in serum Cr from baseline to 12 weeks (odds ratio = 1.25 [CI 1.03–1.55], p = 0.03) and proteinuria at 12 weeks (odds ratio = 0.71 [CI 0.49–0.95], p = 0.05) as independent predictive factors for CRR. Receiver operating characteristic curve analysis suggested proteinuria ≤ 0.8 g/gCr at 12 weeks as the best cutoff to predict CRR. Conclusions The serum Cr decrease and proteinuria ≤ 0.8 g/gCr at 12 weeks were predictors of CRR.